α5β1 integrin is a cell membrane glycoprotein that mediates cell-cell and cell-ECM interactions through its major ligand, fibronectin. α5β1 integrin plays a role in cell migration, differentiation and survival. Levels of α5β1 integrin are elevated in tumor vascular endothelium (e.g., gastric, colorectal hepatocellular, uterocervial, and breast carcinomas) and other angiogenic vessels. α5β1 integrin modulates mural cell association with endothelial cells and the assembly of the endothelial extracellular matrix during angiogenesis. As such, α5β1 integrin is a useful target for inhibition of angiogenesis and sensitization of cells to the effects of a VEGF antagonist.
Thus, there is a need in the art for compositions and methods for targeting α5β1 integrin. The present invention meets this and other needs.